This invention relates to items having inflatable portions and more particularly to inflatable sleds, watercraft, and other objects and methods and techniques for their construction.
Numerous inflatable objects, including products intended for pleasure use in swimming pools or to be towed behind watercraft, are formed of plastics material such as polyvinyl chloride (PVC). Frequently, inflatable chambers or containers are formed by connecting multiple sheets of PVC and sealing the connected portions. Such sealing often occurs through welding, using ultrasonic or radio frequency (RF) energy (or otherwise), the relevant portions of the sheets.
PVC generally welds well to PVC and certain other plastics. It does not, however, typically weld well to numerous other materials such as fabrics. Sewing PVC to fabric similarly produces poor results, as stitching through PVC, particularly when it is in thin-sheet form, may cause the PVC to rip or otherwise lose its ability to retain air.
In some instances, inflating chambers of recreational objects to substantial pressures and covering them with shells might desirably enhance the rigidity of the overall products. The shells might not contain ordinary zippers, however, at least in part because the substantial pressures impinging upon the zippers could deform them and inhibit satisfactory operation (particularly in cold temperatures). Although conceivably heavy-duty zippers could be employed, such zippers also might not work correctly and, at minimum, would add significant expense to the cost of constructing the objects.
The present invention provides alternative methods and techniques for constructing inflatable objects. Objects made according to the invention may include not only PVC and fabric, but also an interfacing material of PVC and meshed fabric. In constructing these objects, the PVC may be welded to the interface and the fabric sewn to it, permitting use of both PVC and fabric in the same object.
Additionally optionally included in some products of the present invention are opposed, spatially-alternating loops through which a rope, stick, or other article may be placed. The loop sets, together with the article placed through them, provide a low-cost fastening system as an alternative to heavy-duty zippers. Preferably designed to be sewn to fabric components of the objects, the loops are especially (although not exclusively) useful in constructing inflatable sleds intended for use in cold weather.
By covering most or all of an inflatable bladder or chamber with a fabric shell, a relatively rigid object may be formed. Attaching the chamber to the shell using the interfacing material facilitates construction of the object. Certain fittings made of PVC or similar material, which otherwise might be connected to the inflatable chamber were it not covered by the shell, may instead likewise be connected to the exterior of the shell using the interfacing material.
It thus is an object of the present invention to provide techniques and methods for constructing inflatable objects.
It is an additional object of the present invention to provide components of inflatable objects in which PVC and fabric need not be welded together directly.
It is a further object of the present invention to provide methods of attaching PVC and fabric, such methods including use of interfacing material formed of PVC and meshed fabric.
It is yet another object of the present invention to provide fastening systems as alternatives to using heavy-duty zippers for products including inflatable portions.
It is also an object of the present invention to provide inflatable sleds and watercraft and methods and techniques for constructing them.
Other objects, features, and advantages of the present invention will be apparent to those skilled in the art with reference to the remaining text and the drawings of this application.